Prior to this I was playing on a lead piece with a larger diameter but shallower cup and tighter bore (venturi) but I was finding it played stuffy and caused me to over-blow if I didn't back off and get my technique perfect. The 10B4 really opened up my sound wihtout sacrificing range. In fact, I get a much fuller sound up there with the deeper cup.
This is a great all-round jazz piece but, of course, it all depends on the shape of your face and what trumpet you are using. If you've been using something like a 13A4a but find it stuffy in the lower register then this might be a good alternative.